Hi, have a 96 c280. I replaced my MAF. This cleared up the symptoms of rough idle, lag while depressing the accelerator. Now about 3 to 4 months later, the symptoms are back. Along with the codes. Also when unplugging the MAF the symptoms continue. Before replacing my MAF when I unplugged it the symptoms went away, that's one of the reasons why I decided to buy a new one. But this time when I unplug the MAF the symptoms stay the same. Any thoughts on how I should proceed?

I had one of these cars and hated to see her go.
Check and replace all the vaccuum lines. The white plastic ones brittle with age.

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Free your heel and your mind will follow!

Who manufacturered the new MAF you installed? It's a shot in the dark, but that part in particular can be really touchy. Ive had more than one "new" one go bad.

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'89 260e (212K Mi.), '92 400e (208K Mi.), '92 400e (not a misprint) (146K Mi.), '95 C220, '81 240D--Sold